8.0 Ignition and
Operation
LIGHTING INSTRUCTIONS
1. Turn manual gas valve to OFF position.
2. Turn electrical supply OFF.
3. Wait at least five (5) minutes.
4. Set thermostat above room temperature.
5. Turn manual gas valve to ON position.
6. Turn electrical supply ON.
7. Set thermostat at desired temperature.
8. If heater does not light, repeat Steps 1-7.
IMPORTANT: The control system cannot determine the
presence of flame if it is not electrically grounded to the
burner; the control system will lockout and shut off. The
control is extremely polarity sensitive. Proper grounding and
proper electrical polarity are essential to the operation of
these heaters.
SEQUENCE OF OPERATION
1. Thermostat calls for heat. (2-stage models: low-heat or high-heat operation is
determined by setpoints of the thermostat. Refer to thermostat manufacturer's
instructions.)
2. Power is applied to the Ignition Detection Control (IDC). 15 seconds after power
is applied, a spark is developed at the electrodes and the combination gas valve
opens for a 15-second trial-for-ignition period.
3. Burner ignites; a small DC electrical current begins flowing from sensing electrode
through flame to ground.
4. The controller senses current, turns OFF spark, gas continues to flow through
the combination gas valve. (Sparking may continue for the full 15 seconds before
stopping.)
5. Should the burner fail to light or flame is not detected during the first trial-for-
ignition period, the combination gas valve is de-energized and the controller starts
the 15-second inter-purge sequence before another ignition trial. After 15 seconds,
the controller begins two (2) more ignition trials.
If the burner fails to light after the third trial, the controller will de-energize the gas
valve and go into lockout mode.
6. On flame outage at the sensing electrode, the controller responds and begins
sparking within 0.8 seconds. A 15-second trial-for-ignition period begins to re-light
the burner. If flame is re-established, normal operation resumes. (Sparking may
continue for the full 15 seconds before stopping.) Should the burner fail to light or
flame is not detected during the first trial-for-ignition period, the combination gas
valve is de-energized and the controller starts the 15-second inter-purge sequence
before another ignition trial. After 15 seconds, the controller begins two (2) more
ignition trials.
If the burner fails to light after the third trial, the controller will de-energize the gas
valve and go into lockout mode.
7. For lockout recovery, reset the thermostat below the ambient temperature or
disconnect electrical power supply for 5 seconds.
SHUTDOWN
• To shutdown the heater for a week or less, switch off the electrical supply to the
heater.
• To shutdown the heater for more than one week, switch off the electrical supply to
the heater and turn off the gas supply at the gas isolation valve.
Form I-RIH, P/N 131793R8, Page 14
